We intercepted no transmissions. This is a consular ship. We're on a diplomatic mission-- Darth Vader: "If this is a consular ship, where is the Ambassador?"
Darth Vader and his Imperial Stormtroopers had been trying to find the plans to the Death Star. He tries to extract information from Captain Antilles, who was being lifted off of his feet by the neck. After failing to give the whereabouts of the plans, Antilles's neck is crushed by Vader, killing him.